A systematic review of Cernilton for the treatment of benign prostatic hyperplasia

Objective To systematically review the evidence for the clinical effects an d safety of the rye-grass pollen extract (Cernilton) in men with symptomati c benign prostatic hyperplasia (BPH). Methods Trials were identified by searching Medline, specialized databases (EMBASE, Cochrane Library, Phytodok), bibliographies, and contacting releva nt trialists and manufacturers. Randomized or controlled clinical trials we re included if: men with symptomatic BPH were treated with Cernilton; a con trol group received either placebo or pharmacological therapy; the treatmen t duration was greater than or equal to 30 days; and clinical outcomes were reported. Results In all, 444 men were enrolled in two placebo-controlled and two com parative trials lasting 12-24 weeks. Three studies used a double-blind meth od although the concealment of treatment allocation was unclear in all. Cer nilton improved 'self-rated urinary symptoms' (the proportion reporting sat isfactory or improving symptoms) vs placebo and another plant product, Tade nan. The weighted mean (95% confidence interval) risk ratio (RR) for self-r ated improvement vs placebo was 2.40 (1.21-4.75) and the weighted RR vs Tad enan was 1.42 (1.21-4.75). Cernilton reduced nocturia compared with placebo or Paraprost (a mixture of amino acids); against placebo, the weighted RR was 2.05 (1.41-3.00), and against Paraprost the weighted mean difference fo r nocturia was - 0.40 times per evening (-0.73 to 0.07). Cernilton did not improve urinary flow rates, residual volume or prostate size compared with placebo or the comparative study agents. Adverse events were rare and mild; the withdrawal rate for Cernilton was 4.8%, compared with 2.7% for placebo and 5.2% for Paraprost. Conclusions The Cernilton trials analysed were limited by their short durat ion, limited number of enrolees, omissions in reported outcomes, and the un known quality of the preparations used. The comparative trials had no confi rmed active control. The available evidence suggests that Cernilton is well tolerated and modestly improves overall urological symptoms, including noc turia. Additional randomized placebo and active-controlled trials are neede d to evaluate the long-term clinical effectiveness and safety of Cernilton.